U.S. patent number 11,390,998 [Application Number 16/970,997] was granted by the patent office on 2022-07-19 for flame retardant paper.
This patent grant is currently assigned to Toray Industries, Inc.. The grantee listed for this patent is Toray Industries, Inc.. Invention is credited to Hideaki Karasaki, Kazuya Nishioka, Tomoko Takano.
United States Patent |
11,390,998 |
Karasaki , et al. |
July 19, 2022 |
Flame retardant paper
Abstract
A flame retardant paper includes pulp, aluminum hydroxide,
guanidine phosphate and guanidine sulfamate, wherein the content of
the pulp is 10 to 35% by mass and the content of the aluminum
hydroxide is 40 to 70% by mass, and the total content of the
guanidine phosphate and the guanidine sulfamate is 0.1 to 10% by
mass based on the contents of the flame retardant paper.
Inventors: |
Karasaki; Hideaki (Otsu,
JP), Takano; Tomoko (Otsu, JP), Nishioka;
Kazuya (Otsu, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Toray Industries, Inc. |
Tokyo |
N/A |
JP |
|
|
Assignee: |
Toray Industries, Inc. (Tokyo,
JP)
|
Family
ID: |
1000006442876 |
Appl.
No.: |
16/970,997 |
Filed: |
February 25, 2019 |
PCT
Filed: |
February 25, 2019 |
PCT No.: |
PCT/JP2019/006977 |
371(c)(1),(2),(4) Date: |
August 19, 2020 |
PCT
Pub. No.: |
WO2019/167860 |
PCT
Pub. Date: |
September 06, 2019 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20200399833 A1 |
Dec 24, 2020 |
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Foreign Application Priority Data
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Mar 2, 2018 [JP] |
|
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JP2018-037125 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D21H
5/0002 (20130101); D21H 21/34 (20130101); D21H
17/675 (20130101); D21H 21/143 (20130101) |
Current International
Class: |
D21H
21/34 (20060101); D21H 21/14 (20060101); D21H
17/67 (20060101) |
Field of
Search: |
;162/159 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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57-171799 |
|
Oct 1982 |
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JP |
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11-108409 |
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Apr 1999 |
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JP |
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2000-8299 |
|
Jan 2000 |
|
JP |
|
2004-36042 |
|
Feb 2004 |
|
JP |
|
2013-2003 |
|
Jan 2013 |
|
JP |
|
2014/088019 |
|
Jun 2014 |
|
WO |
|
2017/002863 |
|
Jan 2017 |
|
WO |
|
Primary Examiner: Halpern; Mark
Attorney, Agent or Firm: DLA Piper LLP (US)
Claims
The invention claimed is:
1. A flame retardant paper comprising pulp, aluminum hydroxide,
guanidine phosphate, carbon fibers and guanidine sulfamate, wherein
the content of said pulp is 10 to 35% by mass and the content of
said aluminum hydroxide is 40 to 70% by mass, and the total content
of said guanidine phosphate and said guanidine sulfamate is 0.1 to
10% by mass based on the contents of said flame retardant
paper.
2. The flame retardant paper according to claim 1, wherein the
content of said pulp is 20 to 35% by mass, and the total content of
said guanidine phosphate and said guanidine sulfamate is 0.3 to 9%
by mass.
3. The flame retardant paper according to claim 1, wherein a mass
ratio of said guanidine sulfamate to said guanidine phosphate
(guanidine sulfamate/guanidine phosphate) is 5/95 or more and 30/70
or less.
4. A radio wave absorbing sheet comprising the flame retardant
paper according to claim 1.
Description
This application is a 371 of PCT/JP2019/006977 filed 25 Feb.
2019.
TECHNICAL FIELD
This disclosure relates to a flame retardant paper.
BACKGROUND
Development of flame retardant paper has been conventionally
demanded in many fields. For example, paper is widely used in
electric/electronic materials, industrial materials and the like,
and in some of these fields, there is an increasing demand for
development of flame retardant paper.
Known methods of imparting flame retardancy to paper include
coating or impregnating with a flame retardant agent, internally
adding a flame retardant organic substance or inorganic powder,
mixing with an inorganic fiber to make paper, a combination thereof
and the like. More specifically, for example, a flame retardant
paper containing flame retardant fibers and aluminum hydroxide has
been proposed (see WO 2014/088019).
Furthermore, flame retardant paper for a member of a radio wave
absorber used in an anechoic chamber or the like is used for 10
years or more. It is desired that the reduction in the flame
retardancy during this period is suppressed.
To solve the above-mentioned demands, a flame retardant paper for a
member of a radio wave absorber, containing pulp and a flame
retardant agent composed of aluminum hydroxide and polyborate, has
been proposed (see WO 2017/002863).
The flame retardant paper and the flame retardant paper for a
member of a radio wave absorber proposed in WO '019 and WO '863 are
fragile and torn, for example, upon drying in a process of
providing reagent by way of impregnation, coating or the like as
well as during secondary processing such as slitting or printing.
This results in a processing problem of significantly reduced
productivity. In addition, when the flame retardant paper is
corrosive to metal used in the equipment for production, the flame
retardant paper tends to corrode the metal part of the equipment
for production which is in direct contact with the flame retardant
paper, which causes a problem of deterioration of the equipment for
production.
Therefore, it could be helpful to provide a flame retardant paper
that is less likely to be torn upon drying in a process of
providing reagent by way of impregnation, coating or the like as
well as during secondary processing such as slitting or printing
and that has low corrosiveness to metal of the equipment for
production, in addition to high flame retardancy which is suitable
for a member of a radio wave absorber.
SUMMARY
We thus provide:
(1) A flame retardant paper comprising pulp, aluminum hydroxide,
guanidine phosphate and guanidine sulfamate, wherein the content of
the pulp is 10 to 35% by mass, the content of the aluminum
hydroxide is 40 to 70% by mass, and the total content of the
guanidine phosphate and the guanidine sulfamate is 0.1 to 10% by
mass, given that each of the contents is with respect to the
entirety of the flame retardant paper. (2) The flame retardant
paper according to (1), wherein the content of the pulp is 20 to
35% by mass and the total content of the guanidine phosphate and
the guanidine sulfamate is 0.3 to 9% by mass. (3) The flame
retardant paper according to (1) or (2), wherein the mass ratio of
guanidine sulfamate to guanidine phosphate (guanidine
sulfamate/guanidine phosphate) contained in the flame retardant
paper is 5/95 or more and 30/70 or less. (4) The flame retardant
paper according to any one of (1) to (3), further comprising a
conductive sub stance. (5) A radio wave absorbing sheet in which
the flame retardant paper according to (4) is used.
A flame retardant paper that is less likely to be torn upon drying
in a process of providing reagent by way of impregnation, coating
or the like as well as during secondary processing such as slitting
or printing and that has low corrosiveness to metal of the
equipment for production in addition to high flame retardancy can
be obtained.
DETAILED DESCRIPTION
Our flame retardant paper is described below by way of
examples.
The flame retardant paper is a flame retardant paper comprising
pulp, aluminum hydroxide, guanidine phosphate and guanidine
sulfamate, wherein the content of the pulp is 10 to 35% by mass,
the content of the aluminum hydroxide is 40 to 70% by mass, and the
total content of the guanidine phosphate and the guanidine
sulfamate is 0.1 to 10% by mass, given that each of the contents is
with respect to the entirety of the flame retardant paper.
Examples of the pulp used in the flame retardant paper include pulp
made of plant fibers such as softwood pulp, hardwood pulp,
thermomechanical pulp, groundwood pulp, linter pulp or hemp pulp,
pulp made of recycled fibers such as rayon, and synthetic fiber
pulp made of vinylon, polyester, or the like. One of these pulps or
two or more of these pulps can be appropriately selected and
used.
The flame retardant paper contains 10 to 35% by mass of pulp with
respect to the entirety of the flame retardant paper. When the pulp
content is less than 10% by mass, the entanglement force of the
pulp in the papermaking process is weak, resulting in difficult
formation of a sheet shape. In addition, the content of the pulp is
preferably 17% by mass or more, and more preferably 20% by mass or
more because formation of the sheet shape in the papermaking
process is easier and, furthermore, tearing of the flame retardant
paper or the like is suppressed upon drying in a process of
providing reagent that imparts flame retardancy by way of
impregnation, coating or the like (also referred to as process of
providing reagent) as well as during secondary processing such as
slitting or printing.
On the other hand, when the content of the pulp exceeds 35% by
mass, flame retardancy which is sufficient as a flame retardant
paper may not be obtained.
Thus, when the content of the pulp is 10 to 35% by mass, it is
possible to obtain a sheet of flame retardant paper having
excellent flame retardancy.
The flame retardant paper contains 40 to 70% by mass of aluminum
hydroxide. Aluminum hydroxide is preferably supported uniformly on
the flame retardant paper. In addition, the aluminum hydroxide is
preferably powder.
The aluminum hydroxide is dehydrated and decomposed at a high
temperature, and the resulting endothermic action provides an
effect of flame retardancy. This flame retardancy does not
deteriorate over time even after long-term storage and the effect
of flame retardancy is maintained.
Further, by appropriately adding a papermaking reagent such as a
retention agent or a paper-strengthening agent made of a cationic
polymer compound or an anionic polymer compound during the
papermaking of flame retardant paper, aluminum hydroxide is
adsorbed on the pulp, which contributes to the improved flame
retardancy of the flame retardant paper.
Further, since aluminum hydroxide is a white powder, when the flame
retardant paper is used in a radio wave absorber for an anechoic
chamber, for example, the indoor lighting effect can be enhanced.
Furthermore, aluminum hydroxide does not discolor and can keep the
flame retardant paper white.
When the content of the aluminum hydroxide is less than 40% by
mass, the flame retardant paper may not have sufficient flame
retardancy. Furthermore, when used as a flame retardant paper for a
member of a radio wave absorber, since the pulp content in the
flame retardant paper is increased, discoloration over time becomes
noticeable.
On the other hand, when the content of the aluminum hydroxide
exceeds 70% by mass, high flame retardancy of the flame retardant
paper can be obtained, but the entanglement force of the pulp in
the papermaking process is weak, resulting in difficult formation
of a sheet shape.
Thus, when the content of the aluminum hydroxide is 40 to 70% by
mass, it is possible to obtain a sheet of flame retardant paper
having excellent flame retardancy and retaining whiteness. Aluminum
hydroxide can be purchased from Wako Pure Chemical Corporation,
Sigma-Aldrich Japan, and the like.
Further, the flame retardant paper contains 0.1 to 10% by mass in
total of guanidine phosphate and guanidine sulfamate.
Generally, the higher the content of the reagent that imparts flame
retardancy is, the higher the flame retardancy of the flame
retardant paper is. However, a large content of the reagent that
imparts flame retardancy tends to cause tearing of the flame
retardant paper or the like upon drying in a process of providing
reagent that imparts flame retardancy by way of impregnation,
coating or the like (hereinafter, also referred to as process of
providing reagent) as well as during secondary processing such as
slitting or printing. It is believed that this is because the large
content of the reagent that imparts flame retardancy results in
decreased toughness of the flame retardant paper. When guanidine
phosphate and guanidine sulfamate are used in combination, the
required amount for improving the flame retardancy of the flame
retardant paper containing a certain amount or more of pulp can be
reduced compared to the required amount of a polyborate or the
like. Therefore, it is possible to impart high flame retardancy to
the flame retardant paper as well as to maintain the toughness of
the flame retardant paper which is suitable for drying in the
process of providing reagent by way of impregnation, coating or the
like as well as for secondary processing such as slitting and
printing. Further, guanidine sulfamate exhibits hygroscopicity and
therefore can impart flexibility to the flame retardant paper due
to the water content. Thus, the handling property of the flame
retardant paper can be improved.
When the total content of the guanidine phosphate and the guanidine
sulfamate with respect to the entirety of the flame retardant paper
is 0.1% or less, the flame retardancy of the flame retardant paper
tends to be insufficient. For the above reason, the total content
of the guanidine phosphate and the guanidine sulfamate with respect
to the entirety of the flame retardant paper is preferably 0.3% by
mass or more.
On the other hand, when the total content of the guanidine
phosphate and the guanidine sulfamate with respect to the entirety
of the flame retardant paper is 10% or more, a flame retardant
paper can be torn or the like upon drying in a process of providing
reagent by way of impregnation, coating or the like as well as
during secondary processing such as slitting or printing, leading
to deterioration of the handling property and passage of processes.
Further, in a member stuck on another molded body such as foamed
plastic or the like, sufficient flame retardancy may not be
obtained. For the above reason, the total content of the guanidine
phosphate and the guanidine sulfamate with respect to the entirety
of the flame retardant paper is preferably 9% by mass or less.
The mass ratio of the guanidine sulfamate to the guanidine
phosphate (guanidine sulfamate/guanidine phosphate) in the flame
retardant agent is preferably 5/95 or more and 30/70 or less.
When the mass ratio of the guanidine sulfamate to the guanidine
phosphate (guanidine sulfamate/guanidine phosphate) is 5/95 or
more, tearing of the flame retardant paper or the like can be
suppressed upon drying in a process of providing reagent by way of
impregnation, coating or the like as well as during secondary
processing such as slitting or printing.
On the other hand, when the mass ratio of the guanidine sulfamate
to the guanidine phosphate (guanidine sulfamate/guanidine
phosphate) is 30/70 or less, the corrosiveness to metal of the
equipment for production can be suppressed.
The flame retardant paper may contain an inorganic fiber such as a
glass fiber, mineral wool or a basalt fiber. Since these are
inorganic fibers, they can improve the flame retardancy of the
flame retardant paper. Furthermore, since these rigid fibers can
exhibit a high degree of rigidity in the flame retardant paper, the
handling property of the flame retardant paper can be improved. The
content of the inorganic fiber is preferably 1 to 30% by mass when
the entire flame retardant paper is considered as 100% by mass. The
content of the inorganic fibers is more preferably 15% by mass or
less. Within this range, flame retardant paper having a high degree
of rigidity can be stably manufactured.
The flame retardant paper can contain a conductive substance. The
conductive substance is, when the flame retardant paper is used as
a flame retardant paper for a member of a radio wave absorber, a
material that converts radio wave energy into a minute electric
current and further converts into heat energy to attenuate the
radio wave, that is, to absorb radio waves. Examples of the
conductive substance include conductive particles and conductive
fibers. Examples of the conductive particles herein include metal
particles, carbon black particles, carbon nanotube particles,
carbon microcoil particles, graphite particles and the like.
Examples of the conductive fibers include carbon fibers, metal
fibers and the like, and examples of the metal fibers include
stainless fibers, copper fibers, silver fibers, gold fibers, nickel
fibers, aluminum fibers, iron fibers and the like. Furthermore, the
conductive substance can also include non-conductive particles and
fibers to which conductivity is imparted by plating, vapor
deposition, thermal spraying or the like with metal.
Among these conductive substances, conductive fibers are preferably
used, and among the conductive fibers, conductive short fibers are
preferably used. Since the conductive short fibers have a large
aspect ratio, the fibers are likely to come into contact with each
other. Therefore, compared to the powder, the performance of radio
wave absorption can be effectively obtained even in a small amount.
Further, among the conductive short fibers, carbon fibers are
particularly preferably used because the fibers are rigid and
easily oriented in the substrate, and show almost no change in the
performance during the long-term use. The length of the conductive
short fibers is preferably 0.1 mm or more, and more preferably 1.0
mm or more from the viewpoint of the easy contact between the
fibers and the dispersibility of the slurry in the papermaking
process, which will be described later. On the other hand, the
length of the conductive short fibers is preferably 15.0 mm or
less, and more preferably 10.0 mm or less.
In the flame retardant paper, the content of the conductive
substance is preferably 0.05 parts by mass or more and 5 parts by
mass or less with respect to 100 parts by mass of the raw material
of the flame retardant paper excluding the conductive substance.
Further, the content thereof is preferably 0.1 parts by mass or
more, and more preferably 0.3 parts by mass or more. On the other
hand, the content thereof is preferably 4 parts by mass or less,
and more preferably 3 parts by mass or less.
The flame retardant paper preferably has a basis weight of 50 to
200 g/m.sup.2. When the basis weight is in this range, the
toughness of the flame retardant paper is improved, which can
prevent the flame retardant paper from being torn or the like upon
drying in a process of providing reagent to the flame retardant
paper by way of impregnation, coating, or the like as well as
during secondary processing such as slitting or printing. The basis
weight is preferably 80 g/m.sup.2 or more. On the other hand, the
basis weight is preferably 150 g/m.sup.2 or less.
The method of producing the flame retardant paper will be described
below.
As an example of the method of producing the flame retardant paper,
the following papermaking method with paper materials can be used.
A wet papermaking method can be used, in which a slurry is prepared
by mixing constituent materials of the flame retardant paper, which
are fibers (pulp), aluminum hydroxide and the like, with water, and
then made into paper with a paper machine.
Examples of the paper machine include a cylinder wire, a
short-fourdrinier wire, a Fourdrinier wire, Birch former, Roto
former, hydroformer, and the like. Any paper machine can be used.
Examples of dryers include Yankee type dryers, multi-cylinder type
dryers, through-type dryers and the like. Any dryer can be
used.
The method of incorporating guanidine phosphate and guanidine
sulfamate into the flame retardant paper is not particularly
limited. Examples thereof include application by impregnation, by
coating and the like. For the application by impregnation or by
coating, a coating device such as a size press coater, a roll
coater, a blade coater, a bar coater or an air knife coater can be
used, and these devices can be used on-machine or off-machine.
Examples of the method of adding conductive fibers to the flame
retardant paper include a method in which the conductive fibers are
mixed into the slurry described above and incorporated into the
flame retardant paper, a method in which the conductive fibers are
mixed into a binder resin material and coated on the flame
retardant paper using a device such as a size press coater, a roll
coater, a blade coater, a bar coater, or an air knife coater and
the like.
EXAMPLES
The flame retardant paper will be further described in detail in
the following Examples. The values in performance shown in Examples
are measured by the following methods.
Measurement Methods
(1) Identification of Guanidine Phosphate and Guanidine
Sulfamate
A 200 mm.times.200 mm test piece of flame retardant paper is
immersed for 10 minutes in 500 mL of hot water at 100.degree. C.
filled in a 1 L container. The test piece is then taken out from
the hot water and washed with 50 mL of water at room temperature
for 5 minutes. Then, 50 mL of the remaining hot water and 50 mL of
the water at room temperature after the test piece was taken out
were put into a 300 mL container and dried at 80.degree. C. for 12
hours. The precipitated solid was photographed by an ultrahigh
resolution field emission type scanning electron microscopy (SEM,
SU-8010 model manufactured by Hitachi High-Tech Corporation) at
five (5) areas in total which were selected at random in the solid,
and the presence of specific elements was confirmed by an energy
dispersive X-ray analyzer (EDX). Furthermore, together with the
results obtained by measuring the above solid with an infrared
spectrophotometer (FT-IR, IR PRESTIGE-21 manufactured by Shimadzu
Corporation), the presence or absence of guanidine phosphate and
guanidine sulfamate in the flame retardant paper as well as the
content of each of guanidine phosphate and guanidine sulfamate are
determined.
(2) Identification of Other Components than Guanidine Phosphate and
Guanidine Sulfamate
The test piece of the above-mentioned flame retardant paper washed
in (1) is dried at 150.degree. C. for 10 minutes. Using an
ultrahigh resolution field emission type scanning electron
microscopy (SEM, SU-8010 model manufactured by Hitachi High-Tech
Corporation), five (5) areas in total of the dried test piece,
including four (4) area points around points shifted by 5 cm in the
vertical and horizontal directions from the four (4) corners of the
test piece towards the center of the test piece and one area around
a point at the center of the test piece, are photographed. The
presence of specific elements is confirmed by an energy dispersive
X-ray analyzer (EDX), and together with the measurement results of
the above test piece obtained with an infrared spectrophotometer
(FT-IR, IR PRESTIGE-21 manufactured by Shimadzu Corporation) and
the results obtained in (1), the presence or absence of other
components than guanidine phosphate and guanidine sulfamate in the
flame retardant paper as well as the content of other components
than guanidine phosphate and guanidine sulfamate are
determined.
(3) Basis Weight of Flame Retardant Paper
Five sheets of flame retardant paper are cut into squares each
having a side of 300 mm to measure the mass which is converted to
the mass per 1 m.sup.2, and the average value is taken to calculate
the basis weight.
(4) Flame Retardancy of Flame Retardant Paper
Evaluation is based on 20-mm Vertical Combustion Test (UL94 V-0) in
the UL94 Safety Standards ("Tests for Flammability of Plastic
Materials for Parts in Devices and Appliances"). UL herein is
safety standards for accepted electronic products which is
established by Underwriters Laboratories Inc., the United States.
UL94 is the standard for flame retardancy as well.
Pass: For the standard of all the five, the time for burning of the
distance of 100 mm (from the line at 25 mm to the line at 125 mm)
is measured, and the burning rate is calculated, and there should
be no sample burning at a burning rate exceeding 40 mm/min.
Alternatively, it has to be a sample with its fire extinguished
before the combustion or the fire reaches the line at 125 mm. Fail:
At least one of the five does not meet the above pass criteria. (5)
Flame Retardancy of a Member Obtained by Sticking Flame Retardant
Paper and Expanded Polystyrene
A flame retardant paper and a 10-mm thick expanded polystyrene are
stuck each other with a double-sided tape (recycled paper
double-sided tape NWBB-15, manufactured by NICHIBAN CO., LTD.) to
prepare a member in which the flame retardant paper and the
expanded polystyrene are joined.
The above-described member is evaluated for the burning rate in
accordance with Horizontal Burning Foamed Material Test (UL94 HBF)
in the UL94 Safety Standards ("Tests for Flammability of Plastic
Materials for Parts in Devices and Appliances").
Pass: Among five samples having a dimension of 150 mm (length) and
50 mm (width), the time for burning of the length of 100 mm (from
the line at 25 mm to the line at 125 mm) is measured, and the
burning rate is calculated, and there should be no sample burning
at a burning rate exceeding 40 mm/min. Alternatively, it has to be
a sample with its fire extinguished before the combustion reaches
the line at 125 mm. Fail: At least one of the five does not meet
the above pass criteria. (6) Tearability
The presence or absence of tearing of the flame retardant paper was
confirmed by the following method. The flame retardant paper cut
into a 100-mm square is dried at 80.degree. C. for 120 seconds,
cooled at room temperature for 10 seconds, followed by repeated
mountain folds and valley folds. The number of the folding times
when a rip occurs at the crease is recorded (upper limit is 20
times). It can be considered that as the number of the folding
times until a rip occurs increases, the flame retardant paper is
less likely to be torn.
(7) Corrosiveness to Metal
The flame retardant paper is fixed with an iron clip, and after a
high humidity treatment (temperature of 60.degree. C., humidity of
90%, treatment duration of 1 week), the presence or absence of the
corrosion of the clip is confirmed.
Evaluation Criteria
A: No corrosion is confirmed.
B: Corrosion is confirmed on part of the clip.
C: Corrosion is confirmed on the entire clip.
(8) Complex Permittivity
Using a rectangular waveguide (manufactured by Kanto Electronic
Application and Development Inc.), the complex permittivity at 3.0
GHz was calculated using the S-parameter method. The S-parameter
method is a method in which the reflection (S11) and transmission
(S21) of a sample inserted in the middle of a transmission line are
measured with a network analyzer (Agilent Technologies, Inc.) to
obtain a complex permittivity. The real part of the complex
permittivity was .epsilon..sup.R and the imaginary part was
.epsilon..sup.J.
The real part .epsilon..sup.R of the complex permittivity is a term
corresponding to a normal relative permittivity. When the real part
.epsilon..sup.R of the complex permittivity is too small, the radio
wave cannot be efficiently attenuated because the compression of
the wavelength of the radio waves taken into the absorbing material
is small. Further, when the real part .epsilon..sup.R of the
complex permittivity is too large, radio waves tend to be reflected
on the surface of the absorbing material.
The imaginary part .epsilon..sup.J of the complex permittivity is a
term due to the electrical loss, and this term allows for the
conversion of radio wave energy into heat energy for the radio wave
attenuation. When the imaginary part .epsilon..sup.J of the complex
permittivity is too small, the attenuation of radio waves in the
absorbing material tends to be small while too a large imaginary
part .epsilon..sup.J of the complex permittivity indicates the
tendency of the reflection on the surface of the absorbing
material.
Evaluation Criteria
A: Both the real part .epsilon..sup.R and the imaginary part
.epsilon..sup.J of the complex permittivity are 10 or more, and the
performance of the radio wave absorption is exhibited.
B: Both the real part .epsilon..sup.R and the imaginary part
.epsilon..sup.J of the complex permittivity are less than 10, and
the performance of the radio wave absorption is not exhibited.
Example 1
First, 15% by mass of softwood pulp having a fiber length of 5 mm
as pulp, 65% by mass of aluminum hydroxide (Wako Pure Chemical
Corporation) and 15% by mass of glass fibers were mixed to perform
wet papermaking in the continuous papermaking method. Thus, a flame
retardant paper was obtained.
Using a size press coater, a flame retardant agent containing
guanidine phosphate (product name "Nonnen" (registered trademark)
985, manufactured by Marubishi Oil Chemical Co., LTD.) and
guanidine sulfamate (product name SG-2 (trade name), manufactured
by Dainippon Ink and Chemicals, Inc.) was applied in an amount of
5% by mass with respect to the entirety of the flame retardant
paper. Thus, a flame retardant paper having a basis weight of 108
g/m.sup.2 was obtained. The mass ratio of the guanidine sulfamate
to the guanidine phosphate (guanidine sulfamate/guanidine
phosphate) was 10/90.
The resulting flame retardant paper was evaluated. The results are
shown in Table 1. The burning rate of the flame retardant paper was
slow and passed UL94 V-0. The burning rate of the member stuck on
expanded polystyrene was also slow and passed UL94 HBF. In
addition, the tearability was good, and the corrosiveness by the
flame retardant paper to the metal was not observed, either. The
performance of the radio wave absorption was not exhibited.
Example 2
A flame retardant paper having a basis weight of 108 g/m.sup.2 of
Example 2 was obtained in the same manner as in Example 1 except
that the pulp and the aluminum hydroxide of Example 1 were 20% by
mass and 60% by mass, respectively.
The resulting flame retardant paper was evaluated. The results are
shown in Table 1. The burning rate of the flame retardant paper was
slow, and passed UL94 V-0. The burning rate of the member stuck on
expanded polystyrene was also slow, and passed UL94 HBF. In
addition, the tearability was good, and the corrosiveness by the
flame retardant paper to the metal was not observed, either. The
performance of the radio wave absorption was not exhibited.
Example 3
A flame retardant paper having a basis weight of 108 g/m.sup.2 of
Example 3 was obtained in the same manner as in Example 1 except
that the pulp and the aluminum hydroxide of Example 1 were 30% by
mass and 50% by mass, respectively.
The resulting flame retardant paper was evaluated. The results are
shown in Table 1. The burning rate of the flame retardant paper was
slow and passed UL94 V-0. The burning rate of the member stuck on
expanded polystyrene was also slow and passed UL94 HBF. In
addition, the tearability was good, and the corrosiveness by the
flame retardant paper to the metal was not observed, either. The
performance of the radio wave absorption was not exhibited.
Example 4
A flame retardant paper having a basis weight of 104 g/m.sup.2 of
Example 4 was obtained in the same manner as in Example 2 except
that the aluminum hydroxide and the flame retardant agent of
Example 2 were 64.5% by mass and 0.5% by mass, respectively.
The resulting flame retardant paper was evaluated. The results are
shown in Table 1. The burning rate of the flame retardant paper was
slow and passed UL94 V-0. The burning rate of the member stuck on
expanded polystyrene was also slow and passed UL94 HBF. In
addition, the tearability was good, and the corrosiveness by the
flame retardant paper to the metal was not observed, either. The
performance of the radio wave absorption was not exhibited.
Example 5
A flame retardant paper having a basis weight of 108 g/m.sup.2 of
Example 5 was obtained in the same manner as in Example 2 except
that the pulp, the aluminum hydroxide, and the glass fibers of
Example 2 were 19% by mass, 62% by mass, and 14% by mass,
respectively.
The resulting flame retardant paper was evaluated. The results are
shown in Table 1. The burning rate of the flame retardant paper was
slow and passed UL94 V-0. The burning rate of the member stuck on
expanded polystyrene was also slow and passed UL94 HBF. In
addition, the tearability was good, and the corrosiveness by the
flame retardant paper to the metal was not observed, either. The
performance of the radio wave absorption was not exhibited.
Example 6
A flame retardant paper having a basis weight of 114 g/m.sup.2 of
Example 6 was obtained in the same manner as in Example 2 except
that the pulp, the aluminum hydroxide, the glass fibers, and the
flame retardant agent of Example 2 were 18% by mass, 59% by mass,
13% by mass, and 10% by mass, respectively.
The resulting flame retardant paper was evaluated. The results are
shown in Table 1. The burning rate of the flame retardant paper was
slow and passed UL94 V-0. The burning rate of the member stuck on
expanded polystyrene was also slow and passed UL94 HBF. In
addition, the tearability was good, and the corrosiveness by the
flame retardant paper to the metal was not observed, either. The
performance of the radio wave absorption was not exhibited.
Example 7
A flame retardant paper having a basis weight of 108 g/m.sup.2 of
Example 7 was obtained in the same manner as in Example 2 except
the mass ratio of the guanidine sulfamate to the guanidine
phosphate (guanidine sulfamate/guanidine phosphate) of Example 2
was changed to 15/85.
The resulting flame retardant paper was evaluated. The results are
shown in Table 1. The burning rate of the flame retardant paper was
slow and passed UL94 V-0. The burning rate of the member stuck on
expanded polystyrene was also slow and passed UL94 HBF. In
addition, the tearability was good, and the corrosiveness by the
flame retardant paper to the metal was not observed, either. The
performance of the radio wave absorption was not exhibited.
Example 8
A flame retardant paper having a basis weight of 108 g/m.sup.2 of
Example 8 was obtained in the same manner as in Example 2 except
the mass ratio of the guanidine sulfamate to the guanidine
phosphate (guanidine sulfamate/guanidine phosphate) of Example 2
was changed to 20/80.
The resulting flame retardant paper was evaluated. The results are
shown in Table 1. The burning rate of the flame retardant paper was
slow and passed UL94 V-0. The burning rate of the member stuck on
expanded polystyrene was also slow and passed UL94 HBF. In
addition, the tearability was good, and the corrosiveness by the
flame retardant paper to the metal was not observed, either. The
performance of the radio wave absorption was not exhibited.
Example 9
A flame retardant paper having a basis weight of 108 g/m.sup.2 of
Example 9 was obtained in the same manner as in Example 2 except
the mass ratio of the guanidine sulfamate to the guanidine
phosphate (guanidine sulfamate/guanidine phosphate) of Example 2
was changed to 25/75.
The resulting flame retardant paper was evaluated. The results are
shown in Table 2. The burning rate of the flame retardant paper was
slow and passed UL94 V-0. The burning rate of the member stuck on
expanded polystyrene was also slow and passed UL94 HBF. In
addition, the tearability was good, and the corrosiveness by the
flame retardant paper to the metal was not observed, either. The
performance of the radio wave absorption was not exhibited.
Example 10
A flame retardant paper having a basis weight of 108 g/m.sup.2 of
Example 10 was obtained in the same manner as in Example 2 except
the mass ratio of the guanidine sulfamate to the guanidine
phosphate (guanidine sulfamate/guanidine phosphate) of Example 2
was changed to 50/50.
The resulting flame retardant paper was evaluated. The results are
shown in Table 2. The burning rate of the flame retardant paper was
slow and passed UL94 V-0. The burning rate of the member stuck on
expanded polystyrene was also slow and passed UL94 HBF. In
addition, the tearability was good. However, some corrosion was
observed on part of the clip. The performance of the radio wave
absorption was not exhibited.
Example 11
A flame retardant paper having a basis weight of 108 g/m.sup.2 of
Example 11 was obtained in the same manner as in Example 2 except
that the aluminum hydroxide and the carbon fibers of Example 2 were
59.5% by mass and 0.5% by mass, respectively.
The resulting flame retardant paper was evaluated. The results are
shown in Table 2. The burning rate of the flame retardant paper was
slow and passed UL94 V-0. The burning rate of the member stuck on
expanded polystyrene was also slow and passed UL94 HBF. In
addition, the tearability was good, and the corrosiveness by the
flame retardant paper to the metal was not observed, either. The
performance of the radio wave absorption was exhibited.
Example 12
A flame retardant paper having a basis weight of 108 g/m.sup.2 of
Example 12 was obtained in the same manner as in Example 2 except
that the aluminum hydroxide and the carbon fibers of Example 2 were
59% by mass and 1.0% by mass, respectively.
The resulting flame retardant paper was evaluated. The results are
shown in Table 2. The burning rate of the flame retardant paper was
slow and passed UL94 V-0. The burning rate of the member stuck on
expanded polystyrene was also slow and passed UL94 HBF. In
addition, the tearability was good, and the corrosiveness by the
flame retardant paper to the metal was not observed, either. The
performance of the radio wave absorption was exhibited.
Example 13
A flame retardant paper having a basis weight of 108 g/m.sup.2 of
Example 13 was obtained in the same manner as in Example 12 except
that the pulp and the carbon fibers of Example 12 were 19% by mass
and 2.0% by mass, respectively.
The resulting flame retardant paper was evaluated. The results are
shown in Table 2. The burning rate of the flame retardant paper was
slow and passed UL94 V-0. The burning rate of the member stuck on
expanded polystyrene was also slow and passed UL94 HBF. In
addition, the tearability was good, and the corrosiveness by the
flame retardant paper to the metal was not observed, either. The
performance of the radio wave absorption was exhibited.
Example 14
A flame retardant paper having a basis weight of 108 g/m.sup.2 of
Example 14 was obtained in the same manner as in Example 13 except
that the aluminum hydroxide, the glass fibers and the carbon fibers
of Example 12 were 58% by mass, 14% by mass and 4.0% by mass,
respectively.
The resulting flame retardant paper was evaluated. The results are
shown in Table 2. The burning rate of the flame retardant paper was
slow and passed UL94 V-0. The burning rate of the member stuck on
expanded polystyrene was also slow and passed UL94 HBF. In
addition, the tearability was good, and the corrosiveness by the
flame retardant paper to the metal was not observed, either. The
performance of the radio wave absorption was exhibited.
Example 15
A flame retardant paper having a basis weight of 108 g/m.sup.2 of
Example 15 was obtained in the same manner as in Example 14 except
that the pulp, the aluminum hydroxide and the carbon fibers of
Example 14 were 18% by mass, 57% by mass, and 6.0% by mass,
respectively.
The resulting flame retardant paper was evaluated. The results are
shown in Table 2. The burning rate of the flame retardant paper was
slow and passed UL94 V-0. The burning rate of the member stuck on
expanded polystyrene was also slow and passed UL94 HBF. In
addition, the tearability was good, and the corrosiveness by the
flame retardant paper to the metal was not observed, either. The
performance of the radio wave absorption was exhibited.
TABLE-US-00001 TABLE 1 Unit Example 1 Example 2 Example 3 Example 4
Example 5 Example 6 Example 7 Example 8 Treatment Pulp % by 15 20
30 20 19 18 20 20 mass Aluminum % by 65 60 50 64.5 62 59 60 60
hydroxide mass Glass fibers % by 15 15 15 15 14 13 15 15 mass Flame
retardant % by 5 5 5 0.5 5 10 5 5 agent mass Guanidine % by 4.5 4.5
4.5 0.45 4.5 9.0 4.25 4.0 phosphate (content) mass Guanidine % by
0.5 0.5 0.5 0.05 0.5 1.0 0.75 1.0 sulfamate (content) mass
Polyborate % by -- -- -- -- -- -- -- -- (content) mass Carbon
fibers % by -- -- -- -- -- -- -- -- mass Mass ratio (guanidine --
10/90 10/90 10/90 10/90 10/90 10/90 15/85 20/80 sulfamate/guanidine
phosphate) Basis weight g/m.sup.2 108 108 108 104 108 114 108 108
Flame retardancy of flame -- Pass Pass Pass Pass Pass Pass Pass
Pass retardant paper (UL94 V-0) Flame retardancy of stuck -- Pass
Pass Pass Pass Pass Pass Pass Pass product (UL94 HBF) Tearability
Times 3 7 11 >20 5 3 6 6 Corrosiveness -- A A A A A A A A
Complex permittivity -- B B B B B B B B
TABLE-US-00002 TABLE 2 Unit Example 9 Example 10 Example 11 Example
12 Example 13 Example 14 Example 15 Treatment Pulp % by 20 20 20 20
19 19 18 mass Aluminum % by 60 60 59.5 59 59 58 57 hydroxide mass
Glass fibers % by 15 15 15 15 15 14 14 mass Flame retardant % by 5
5 5 5 5 5 5 agent mass Guanidine % by 3.75 2.5 4.5 4.5 4.5 4.5 4.5
phosphate (content) mass Guanidine % by 1.25 2.5 0.5 0.5 0.5 0.5
0.5 sulfamate (content) mass Polyborate % by -- -- -- -- -- -- --
(content) mass Carbon fibers % by -- -- 0.5 1.0 2.0 4.0 6.0 mass
Mass ratio -- 25/75 50/50 10/90 10/90 10/90 10/90 10/90 (guanidine
sulfamate/ guanidine phosphate) Basis weight g/m.sup.2 108 108 108
108 108 108 108 Flame retardancy of flame -- Pass Pass Pass Pass
Pass Pass Pass retardant paper (UL94 V-0) Flame retardancy of stuck
-- Pass Pass Pass Pass Pass Pass Pass product (UL94 HBF)
Tearability Times 7 18 7 7 7 7 7 Corrosiveness -- A B A A A A A
Complex permittivity B B A A A A A
Comparative Example 1
The method of Example 1 was performed in the same manner except
that the pulp and the aluminum hydroxide of Example 1 were 5% by
mass and 75% by mass, respectively. However, the production was not
stable, and the flame retardant paper of Comparative Example 1 was
not obtained. The results of the evaluation and the like are shown
in Table 3.
Comparative Example 2
A flame retardant paper having a basis weight of 108 g/m.sup.2 of
Comparative Example 2 was obtained in the same manner as in Example
1 except that the pulp, the aluminum hydroxide, and the glass
fibers of Example 1 were 40% by mass, 35% by mass, and 20% by mass,
respectively.
The resulting flame retardant paper was evaluated. The results are
shown in Table 3. The burning rate of the flame retardant paper was
fast and failed UL94 V-0. The burning rate of the member stuck on
expanded polystyrene was also fast and failed UL94 HBF. The
tearability was 13 times. Thus, the above flame retardant paper
showed excellent tearability. The corrosiveness by the flame
retardant paper to the metal was not observed. The performance of
the radio wave absorption was not exhibited.
Comparative Example 3
A flame retardant paper having a basis weight of 100 g/m.sup.2 of
Comparative Example 3 was obtained in the same manner as in Example
4 except that the aluminum hydroxide and the flame retardant agent
of Example 4 were 65% by mass and 0% by mass, respectively.
The resulting flame retardant paper was evaluated. The results are
shown in Table 3. The burning rate of the flame retardant paper was
slow and passed UL94 V-0. On the other hand, the burning rate of
the member stuck on expanded polystyrene was fast and failed UL94
HBF. The tearability was 20 times or more. Thus, the above flame
retardant paper showed excellent tearability. The corrosiveness by
the flame retardant paper to the metal was not observed. The
performance of the radio wave absorption was not exhibited.
Comparative Example 4
A flame retardant paper having a basis weight of 115 g/m.sup.2 of
Comparative Example 4 was obtained in the same manner as in Example
6 except that the aluminum hydroxide and the flame retardant agent
of Example 6 were 58% by mass and 11% by mass, respectively.
The resulting flame retardant paper was evaluated. The results are
shown in Table 3. The burning rate of the flame retardant paper was
slow, and passed UL94 V-0. On the other hand, the burning rate of
the member stuck on expanded polystyrene was fast, and failed UL94
HBF. The tearability was 2 times. Thus, the above flame retardant
paper showed poor tearability. The corrosiveness by the flame
retardant paper to the metal was not observed. The performance of
the radio wave absorption was not exhibited.
Comparative Example 5
A flame retardant paper having a basis weight of 108 g/m.sup.2 of
Comparative Example 5 was obtained in the same manner as in Example
2 except the flame retardant agent containing guanidine phosphate
and guanidine sulfamate of Example 2 was only guanidine
phosphate.
The resulting flame retardant paper was evaluated. The results are
shown in Table 3. The burning rate of the flame retardant paper was
slow, and passed UL94 V-0. On the other hand, the burning rate of
the member stuck on expanded polystyrene was fast, and failed UL94
HBF. The tearability was 4 times. Thus, the above flame retardant
paper showed poor tearability. The corrosiveness by the flame
retardant paper to the metal was not observed. The performance of
the radio wave absorption was not exhibited.
Comparative Example 6
A flame retardant paper having a basis weight of 114 g/m.sup.2 of
Comparative Example 6 was obtained in the same manner as in Example
6 except the flame retardant agent containing guanidine phosphate
and guanidine sulfamate of Example 6 was a polyborate (product name
"SOUFA" (trade name) manufactured by Soufa Inc.).
The resulting flame retardant paper was evaluated. The results are
shown in Table 3. The burning rate of the flame retardant paper was
slow and passed UL94 V-0. The burning rate of the member stuck on
expanded polystyrene was also slow and passed UL94 HBF. The
tearability was 1 time. Thus, the above flame retardant paper
showed poor tearability. The corrosiveness by the flame retardant
paper to the metal was not observed. The performance of the radio
wave absorption was not exhibited.
TABLE-US-00003 TABLE 3 Comparative Comparative Comparative
Comparative Comparative Comparative- Unit Example 1 Example 2
Example 3 Example 4 Example 5 Example 6 Treatment Pulp (content) %
by 5 40 20 18 20 18 mass Aluminum % by 75 35 65 58 60 59 hydroxide
(content) mass Glass fibers % by 15 20 15 13 15 13 (content) mass
Reagent that imparts % by 5 5 0 11 5 10 flame retardancy mass
(total content) Guanidine phosphate % by 4.5 4.5 -- 4.5 5 --
(content) mass Guanidine sulfamate % by 0.5 0.5 -- 0.5 -- --
(content) mass Polyborate (content) % by -- -- -- -- -- 10 mass
Carbon fibers % by -- -- -- -- -- -- mass Mass ratio (guanidine --
10/90 10/90 -- 10/90 -- -- sulfamate/guanidine phosphate) Basis
weight g/m.sup.2 -- 108 100 115 108 114 Flame retardancy of flame
-- -- Fail Pass Pass Pass Pass retardant paper (UL94 V-0) Flame
retardancy of stuck -- -- Fail Fail Fail Fail Pass product (UL94
HBF) Tearability Times -- 13 >20 2 4 1 Corrosiveness -- -- A A A
A A Complex permittivity -- B B B B B B
In Examples 1 to 10, flame retardant papers having excellent flame
retardancy for the flame retardant papers as well as for the
members obtained by sticking the flame retardant papers on expanded
polystyrene, excellent tearability, and excellent corrosiveness to
metal could be obtained. In Examples 11 to 15, in addition to the
above characteristics, flame retardant papers excellent in the
performance of radio wave absorption could be obtained.
On the other hand, in Comparative Example 1, stable production was
not possible. In Comparative Example 2, although the tearability
was excellent, the flame retardancy of the flame retardant paper
and the stuck product was poor. Comparative Example 3 showed
excellent tearability and flame retardancy for the flame retardant
paper, but showed poor flame retardancy for the stuck product. In
Comparative Examples 4 and 5, the flame retardancy of the flame
retardant papers was excellent, but the stuck products showed poor
flame retardancy and tearability. In Comparative Example 6,
although the flame retardant paper and the stuck product were
excellent in flame retardancy, they showed poor tearability.
* * * * *